This invention relates to a group supervision apparatus for an elevator wherein a plurality of cages are dispersed and kept on standby during a period of light traffic.
In a group supervision apparatus for an elevator, cages are dispersed to several floors in the whole building and kept on standby during a period of light traffic, so that hall calls which arise in the future can be responded to in short waiting periods of time. Dispersive standby operations by prior-art group supervision apparatuses for elevators include, for example, methods disclosed in Japanese Patent Application Laid-open No. 54-162357, Japanese Patent Application Laid-open No. 56-48375 and Japanese Patent Application Laid-open No. 59-48366.
Japanese Patent Application Laid-open No. 54-162357 discloses a method of operation wherein the numbers of occurrence of hall calls are counted for individual floors, and using statistics, dispersive standby floors are set to respective floors at which there are many users or on the basis of predicted large number of usage, or the number of cages to stand by at given floors may be determined. Japanese Patent Application Laid-open No. 56-48375 discloses a method of operation wherein a dispersive standby floor is set, and among a plurality of cages, one which is anticipated to reach the dispersive standby floor in the shortest period of time is given a dispersive standby command, whereby the dispersive arrangement of the cages can be promptly performed. In this case, the dispersive standby floor is artificially set at will. Japanese Patent Application Laid-open No. 59-48366 discloses a method of operation wherein a predetermined value is set between corresponding floors or between corresponding cages, and when an interval based on the positions of the cages has exceeded the predetermined value, the cages are moved so as to establish the interval of the set predetermined value, thereby to set dispersive standby floors. According to the prior-art group supervision apparatuses for elevators, cages are dispersed and kept on standby, and consideration is given so as to shorten the response times of the cages to hall calls to occur in the future, that is, the waiting times of users.
The prior-art group supervision apparatuses for elevators have the tendency that dispersive standby floors are fixed or are unevenly set to specified floors. This is inconvenient for some purposes of buildings. Especially in a building such as an apartment house or condominium, usually the dwellers of respective floors utilize the elevator equally. Therefore, in the case where the dispersive standby floors are fixed or biased to the specified floors, the apparent inequality that the service to the dwellers of those floors is better, whereas service to the dwellers of the other floors is worse, takes place and creates a problem.
As regards the apparatus which statistically sets the dispersive standby floors according to the degrees of use, special hardware and software for collecting the statistics of past use are required and make it expensive to realize the installation of the apparatus.